I suggest you to not use specular channel unless your texture looks brighter or darker for your taste. Even for them simple scalar vectors should be enough for most objects.
It’s all roughness now, even on maps with no screen space reflections.
And keep on mind ambient occlusion has zero effect on dynamic lights.
I think it looks full black cuz it reflects the black area but I am not sure.
Try to put your object in closed cube or something, you may also the change the environment color.